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Improved Silymarin Characteristics for Clinical Applications by Novel Drug Delivery Systems
Published in Madhu Gupta, Durgesh Nandini Chauhan, Vikas Sharma, Nagendra Singh Chauhan, Novel Drug Delivery Systems for Phytoconstituents, 2020
Maryam Tabarzad, Fatemeh Ghorbani-Bidkorbeh, Tahereh Hosseinabadi
A silymarin nanoemulsion was developed consisting castor oil, Tween 80, polyvinylpyrrolidone (PVP), Transcutol HP, and water by a membrane emulsification method which is called Shirasu porous glass (SPG). It offered uniform and narrow sized droplets. Furthermore, silymarin nanoparticles were designed through preparation of a silymarin nanoemulsion by the spray drying method. In comparison with conventional wide sized nanoparticles, these nanoparticles have a monodisperse distribution, size of about 210 nm, and 1300-fold improvement in drug solubility. The oral bioavailability of silymarin achieved from the nanoparticles was reported approximately 1.3 times more than what was gained from the commercial preparation. Moreover, silymarin bioactivity of nanoparticles was enhanced in acute liver injury of rat models. It was concluded that silymarin nanoparticles which were developed by SPG membrane emulsification and spray drying methods could offer delivery of silymarin as a poorly water-soluble drug with improved protective characteristics of liver through higher oral bioavailability of nanoparticles (Yang et al., 2013).
Scintillating quantum dots
Published in Sam Beddar, Luc Beaulieu, Scintillation Dosimetry, 2018
Claudine Nì. Allen, Marie-Ève Lecavalier, Sébastien Lamarre, Dominic Larivière
One challenge in the design of -doped glass scintillator is how to homogeneously incorporate into a glassy matrix. Common glass-based scintillators (e.g., cerium-activated lithium glass scintillators) are manufactured by incorporating the inorganic scintillant into the glass matrix through fusion at high temperatures, typically above (Kang et al., 2013). However, this process is incompatible with the production of cQD-doped glass scintillators, because cQDs would be degraded at such temperatures even if the melting temperatures of their bulk material components, (e.g., ), were much higher than (Haynes, 2013). As an example, Goldstein et al. (1992) have observed a large decrease in the melting temperature of (from to ) with decreased size (from 40 to ). To overcome this manufacturing disadvantage, nanoporous glass was tried as a scintillation support in which the cQDs could diffuse. Typically, porous glass with nanopores 10-20 nm in diameter was generated by slowly dissolving porous glass with interconnected pores of diameter using aqueous solution of hydrofluoric acid and ethanol (1% and 20%, respectively). Using a diffusion approach, Létant and Wang in 2006 estimated the QD density in the porous glass close to . Porous glass is suitable for scintillation applications due to its inert character, its transparency, and the ability to hold guest molecules while isolating them through a succession of nanometer-sized cavities, which prevents self-quenching effects.
Poly(lactic-co-glycolic acid) microsphere production based on quality by design: a review
Published in Drug Delivery, 2021
Yabing Hua, Yuhuai Su, Hui Zhang, Nan Liu, Zengming Wang, Xiang Gao, Jing Gao, Aiping Zheng
Recently, there have been numerous new methods reported for the preparation of PLGA microspheres. For protein-loaded microspheres, active self-encapsulation (ASE) is a post-loading method based on absorption of positively charged proteins in microporous PLGA microspheres loaded with negatively charged polysaccharides (trapping agents) (Scheiner et al., 2021). Furthermore, microfluidic systems represent a platform for the production of monodisperse microspheres as they can fabricate PLGA microspheres in a controlled and reproducible manner using the oil/water microemulsion method in microfluidic channels, achieving a uniform sustained-release profile of drugs from the microspheres. Additionally, CFD modeling is used to investigate droplet flow in the microfluidic channel and to simulate the preparation of PLGA microsphere in the microfluidic chip (Jafarifar et al., 2017; Chengcheng et al., 2019). Furthermore, Shirasu porous glass (SPG) premix membrane emulsification has been employed to ensure controlled particle size as the SPG membrane is a porous glass membrane; the dispersed phase passes through the pores of the microporous membrane to form droplets on the surface of the membrane with the action of nitrogen pressure. Under the flushing action of the continuous phase flowing along the membrane surface, the diameter of the droplet reaches a certain value and will be peeled off from the membrane surface to form an emulsion. The microporous membrane with uniform pore size can then be used to control the particle size and distribution of the emulsion (Feng et al., 2014). However, these methods remain far from industrialization.
Preparation and characterization of dexamethasone lipid nanoparticles by membrane emulsification technique, use of self-emulsifying lipids as a carrier and stabilizer
Published in Pharmaceutical Development and Technology, 2021
Membrane emulsification methods and Shirasu porous glass were used to prepare lipid nanoparticles. Self-emulsifying lipids stabilized lipid nanodispersions without the need for other emulsifiers. Unlike non-self-emulsifying lipids, the process parameters namely, pressure on the lipid phase, membrane pore-size and agitation speed of the contentious phase, of membrane emulsification did not affect the size of self-emulsifying lipids. To increase the solubility of water- and lipid-insoluble drugs such as dexamethasone, lipids having high HLB value such as TEGO Cares are preferred. Dexamethasone release from lipid nanoparticle, stabilized with self-emulsifying lipids, was extended without burst effect.
Uniform-sized insulin-loaded PLGA microspheres for improved early-stage peri-implant bone regeneration
Published in Drug Delivery, 2019
Xing Wang, Feng Qi, Helin Xing, Xiaoxuan Zhang, Chunxiang Lu, Jiajia Zheng, Xiuyun Ren
PLGA (D, L-lactide/glycolide 75/25, Mw13 kDa) was purchased from Lakeshore Biomaterials (Birmingham, AL, USA). Shirasu porous glass (SPG) membranes were provided by SPG Technology Co. Ltd. (Miyazaki, Japan). Human recombinant insulin was provided by Wako Industries, Ltd. (Osaka, Japan). Poly vinyl alcohol-217 (PVA-217, polymerization of 1700, hydrolysis of 88.5%) was obtained from Kuraray (Tokyo, Japan). Titanium implant (length of 7 mm, diameter of 3 mm) and titanium disks (diameter of 10 mm, thickness of 1 mm) were provided by Fullerton Technology Co. Ltd. (Beijing, China).